INTERNATIONAL TELECOMMUNICATION UNION ITU-T RECOMMENDATION SUMMARY Rec. No. : X.290 Title : OSI conformance testing methodology and framework for protocol recommendations for CCITT applications -general concepts Study Group : VII - Data Communications Networks Version : Revised Date of adoption : 1992 Notes : Also published as ISO/IEC 9646-1: 1991 The objective of OSI will not be completely achieved until systems can be tested to determine whether they conform to the relevant protocol specification(s). The relevant ones can be OSI CCITT Recommendations or International Standards. Standardized abstract test suites should be developed for each CCITT Recommendation or International Standard which specifies an OSI protocol, for use by suppliers or implementors in self-testing, by users of OSI products, by telecommunications Administrations and recognized private operating agencies, or by other third party testing organizations. This should lead to comparability and wide acceptance of test results produced by different test laboratories, and thereby minimize the need for repeated conformance testing of the same system. The standardization of test suites requires international definition and acceptance of a common testing methodology, together with appropriate testing methods and procedures. It is the purpose of Recommendations X.290 to X.294 to define the methodology, to provide a framework for specifying conformance test suites, and to define the procedures to be followed during testing. Conformance testing involves testing both the capabilities and behaviour of an implementation, and checking what is observed against both the conformance requirements in the relevant CCITT Recommendations or International Standards and what the implementor states the implementation’s capabilities are. The purpose of conformance testing is to increase the probability that different OSI implementations are able to interwork. However it should be borne in mind that the complexity of most protocols makes exhaustive testing impractical on both technical and economic grounds. Also, testing cannot guarantee conformance to a specification since it detects errors rather than their absence. Thus conformance to a test suite alone cannot guarantee interworking. What it does do is give confidence that an implementation has the required capabilities and that its behaviour conforms consistently in representative instances of communication. To order the complete text of this Recommendation, please use the Order Form for ITU-T Recommendations. An electronic version of this form is available on ITUDOC (Winword 2.0: UPI=ITU-5265; ASCII: UPI=ITU-2488).